I saw some gel tests where factory SS197SR expanded unreliably. I think the only one he got good expansion on was a random high vel round about 1770fps (most were closer to 1700fps). Hornady says in their literature expansion down to 1600fps, but the product page has 2000fps as the min muzzle velocity.

The issue with 40grain V-max is not expansion. The ballistics tests I've seen have it clocked at 1700 fps. It does not fully expand, but it tumbles like a SOB and still generates more than lethal wound channels. It also makes adequate penetration depths. That's in standard blue box ammo.

Kiran04 wrote:The issue with 40grain V-max is not expansion. The ballistics tests I've seen have it clocked at 1700 fps. It does not fully expand, but it tumbles like a SOB and still generates more than lethal wound channels. It also makes adequate penetration depths. That's in standard blue box ammo.